Microbicidal disinfecting compositions that include one or more microorganism-destroying antimicrobial agents as an active ingredient are used in a robust array of industrial, personal, and agricultural settings. The lethal effect of many antimicrobial agents towards microorganisms is generally enhanced at acidic pH levels. For this reason, the pH of common antimicrobial agents is typically adjusted downward by an acidifying agent in the preparation of a microbicidal disinfecting composition. Anionic surfactants such as esters of alkyl and aryl sulfates and sulfonates, for example, are often combined with mineral acids and/or organic acids to achieve a level of acidity conducive to acceptable microbicidal activity. Mineral acids such a phosphoric acid, sulfuric acid, and hydrochloric acid, for example, are often used to adjust the pH of alkyl and aryl sulfonated esters to form liquid microbicidal disinfecting compositions. Organic acids such as citric acid and lactic acid, for example, are often used to adjust the pH of alkyl and aryl sulfated or sulfonated esters and to form powder or liquid microbicidal disinfecting compositions.
A microbicidal disinfecting composition prepared with mineral and/or organic acids as the acidifying agent, however, has a tendency become cloudy and show precipitate formation in hard water. This problem is often combated by the addition of chemicals to prevent cloudiness and precipitate formation—likely by decreasing the critical micelle concentration. But the inclusion of additional chemicals into the microbicidal disinfecting composition limits the extent to which the antimicrobial agent may be concentrated. The reliance on organic acid acidifying agents may further impact this physical constraint. These acids are typically weak acids and, as such, require larger quantities to achieve the desired acidic pH level when compared to mineral acids.
The use of organic acids and/or mineral acids as the primary acidifying agent in the preparation of a microbicidal disinfecting composition can complicate handling, storage, and transportation concerns. The limits imposed on the extent of antimicrobial agent concentration by these acidifying agents and, as needed, additional chemicals to alleviate turbidity, can impact storage and transportation efficiencies. Certain mineral acids are also corrosive and may require special handling and disposal procedures.